The second exciting instalment in Enid Blyton's Adventure series, now with a new cover look from rising picture-book star Rebecca Cobb.Why is everyone so afraid of the castle on the hill, and what dark secrets lurk inside its walls? Philip, Dinah, Lucy-Ann, Jack and Kiki the parrot are on holiday in the countryside, staying on the side of Castle Hill. When flashing lights are seen in a distant tower, they decide to investigate - and discover a very sinister plot concealed within its hidden rooms and gloomy underground passages.